Why would he do this?? Is he literally insane? He must know that this comes off as super creepy and weird? Or maybe he does know that, knows that his career is over regardless, and now he's just trolling everyone?

YES! Whoever invented motion smoothing is a monster. It's the worst thing to happen to cinema since colorization. It wouldn't be so bad if it weren't turned on by default, which means that a whole bunch of people who aren't tech-savvy wind up leaving it on and then wonder why movies look so weird.